The pervasiveness, broad reach, and processing capabilities of consumer technologies, including the internet and smartphone devices, has driven the rapid development of research and commercial applications meant to promote physical activity. Unfortunately, researchers have found that commercial physical activity applications (apps) are not often effective, and are not typically evidence-based. The purpose of this study, which was guided by the multiphase optimization strategy (MOST), was to test the individual and combined efficacy of two theory-driven smartphone app modules designed to promote physical activity: guided hierarchical goal setting and points-based feedback. Participants (N = 116) were recruited to participate in a 12-week home-based exercise program, and randomly assigned to one of four conditions. All individuals received a base-app, which contained three components common to eHealth interventions: physical activity tracking, individualized feedback, and weekly theory-based educational modules. One group received this app alone; a second received the base-app plus a points-based feedback module which awarded points, levels, and badges for engaging in physical activity and other in-app functions; a third received the base-app plus a guided goal setting component which aided individuals in setting both distal and proximal physical activity goals by providing goal recommendations and windows that urged gradual progression; and a fourth condition that received all app components. Results demonstrated that individuals in all conditions increased accelerometer-measured moderate to vigorous physical activity (MVPA) by more than 11 minutes per day across the intervention period, while those with access to the points-based feedback module demonstrated higher levels of MVPA when compared to those without the module. Additionally, these individuals demonstrated more favorable outcomes on a number of psychosocial measures (i.e., barriers self-efficacy, exercise self-efficacy, perceived goal setting ability, outcome expectations) and app usage across the intervention. Those with access to in-app goal setting also had higher levels of app usage relative to those without the component. Overall, these findings provide important information for those interested in developing apps aimed at improving physical activity, and lay the groundwork for additional research.